Oven door construction



P 1960 A. P. KELSEN 2,953,108

OVEN DOOR CONSTRUCTION Filed May 1, 1957 2 Sheets-Sheet 1 l VENTOR Grant eter- KelAen ATTORNEY$ Sept. 20, 1960 I A. P. KELSEN 2,953,108

OVEN DOOR CONSTRUCTION Filed May 1, 1957 2 Sheets-Sheet 2 INVENTOR Clrenfi et er KelAen United States PatentC) OVEN DOOR CONSTRUCTION Arent Peter Kelsen, Atlanta, Ga., assignor to Midland- Ross Corporation, a corporation of Ohio Filed May 1, 1957, Ser. No. 656,240

2 Claims. (Cl. 110-173) long baking cycle of about 72 hours, there are occasions. when it is necessary to partially raise the door to inspect,

the transformers being baked. Except at such occasions it is essential to provide tight sealing at the door to pre vent escape of heat and gases from the oven. The doors are relatively massive and the oven temperatures required frequently range from 200 to 300 C. or higher. A considerable expansion of the doors occurs during rises in their temperatures from normal room conditions -to the oven temperatures. that it almost is impossible to open ordinary sliding doors at the elevated oven operating temperatures. In consequence, cooling of the oven substantially. to room temperatures ordinarily becomes necessary before the doors can be slid open for inspection purposes. This cooling procedure is slow and hazardous and also involves considerable loss of time and material interference with and interruption of the continuous baking cycle.

Objects and features of this invention are the provision of sealed movable door structure for high temperature furnaces or ovens that may be readily raised and lowered at any desired time during high temperature oven operation without requiring either shut-off, cooling or other interference with the heating cycle of the oven or furnace.

Further objects and features of the invention are the provision of simple economical structures for the intended purposes that may even be installed as replacements in existing ovens and furnaces.

Other objects and features of the invention will become apparent from the following specification and the accompanying drawings, wherein:

Figure l is a perspective view of an oven equipped with the door construction of this invention;

Figure 2 is a fragmentary diagrammatic illustration of features of the door arrangement of the invention;

Figure 3 is a section on an enlarged scale taken along line 3-3 of Figure 1 and viewed in the direction of the arrows;

Figure 4 is a section taken along line 4-4 of Figure 3;

Figure 5 is a section taken along line 55 of Figure 4;

Figure 6 is a section taken along line 66 of Figure 3; and

Figure 7 is a section taken along line 77 of Figure 6.

Referring to the drawing, the reference character denotes a massive oven useful for example, in baking varnished transformers and intended to be operated at temperatures in the neighborhood of 265 C. in a baking cycle whose length averages about 72 hours.

The oven 10 is provided with a front door 11. In the embodiment shown, this door 11 has relatively mas- As a result, it has been found.

Patented Sept. 20, 1960 ICC . sive dimensions being about 9 feet wide, 11 feet high and about 5 inches thick and weighs about /2 ton- This door 11 is vertically slidable between guiding surfaces of vertical H columns 12 positioned at opposite sides of the oven 10 adjacent its front opening. These columns 12 have substantially H section with one flange removed (see Figure 6) on the front face of each column. A

column 13 having an L section has one of its flanges 13a secured to the remaining front flange 12a of each H column 12. A second column 14 also having an L sec-- tion has one of its flanges 14a secured to the second flange 13b of the first L sectioned column 13. The other flange 14b of the second L sectioned column 14 lies aligned and parallel with the rear inner flange 12b of the- H column 12.

The door '11 is provided with opposite side frame members 15 in this embodiment made up of a pair of joined L members 16 and 17 whose flanges 16a and 17a. are aligned parallelly with and lie between the column flanges 12b and 14b.

Flange 16a lies close to the flange 12b. A sliding seal between the two flanges 16a and 12b is provided as bya gasket 18 of asbestos or other suitable material which is secured to one of the two flanges 1211 or 16a in any conventional way. In the embodiment shown, it is bolted to flange 16a.

Compression of the gasket 18 and maintenance of a tight but sliding seal between the flanges 16a and 12b is effected by a plurality of outwardly biased compression rollers or casters 19 supported at spaced-apart points .along the lengths of the respective flanges 17a ofthe door frame sides 15. Each caster or roller 19 is ro-'. tatably supported on an axle 20 carried between pairs of. brackets 21 mounted on a cross bar 22 which is slidably, guided on a pair of parallel posts 23 secured to a'bracket 24 which in turn is fastened as by bolts 25 to the flange 17a. The cross bar is biased outwardly away from flange 17a as by the compression springs '26 which are mounted on the posts 23. These springs 26 serve to bias the cross bar 22 and hence roller 19 against the inner face of column flange 14b. In consequence, the door 11 is pushed effectively toward the flange 12b causing sealing compression of gasket 18 between flanges 16a and 12b. The springs 26 are of sufficient strength to insure and maintain a tight seal at the gasket 18 at all times. At the same time the rollers 19 roll freely along the surface of flange 14b and permit ready vertical sliding of door 11 from closed to open condition and vice versa during operation of the oven. Expansion of the door during such operation does not prevent its opening since the expansion is taken up by the yielding action of springs 26 at such times. The number of rollers 19 required, their size, the strength of springs 26 and other components is dependent upon the dimensions and weight of the door.

In order to prevent jamming action of the side pieces of the door frame 15 and brackets 24 against the connecting flange 12 of the H columns when the door is slid open or closed, a plurality of guide rollers 28 (Figures 4 and 5) of the trolley type are secured by brackets 29 to the side pieces 17a of the door frame. These rollers 28 are adjusted and set so that they can roll on the flange 14a of L column 14 and thus prevent the door frame 15 from scraping against the H sectioned columns 12 during raising and lowering of the door 11. Their number and characteristics likewise is dependent upon door dimensions.

The door is adapted to be raised and lowered in this embodiment as by the counterweighted chains or cables 30 secured to the door and threaded around sheaves 31 and also secured to a guided counterweight 32 in a hollow casing 33. A hand crank 34 and cable 35 threaded around crank drum 36 and a pulley 37 keyed to one of the sheaves 31 permits manual raising and lowering of the door. Motor means for lifting and lowering the door may be substituted for the hand crank. The same ar rangement of compression and guide rollers may be provided readily for horizontally sliding doors.

Advantages secured with the installation-as above described are that even with the oven operatingat- 265 C., the door can be manually raised or lowered byone man with minimum effort even though weighing about 1,000 lbs, This is in contrast with similar sliding doors not equipped with the compression and guide roller arrangement of this inventionwhich were found to be immovable .1

at 200 C. despite efforts of six men with largecro'wbars V to budgethen a L H The describedstructure is useful with any type of high temperature oven or furnace where expansion of the door with heat prevents free door movement. It is not limited to the baking oven described. A 3

While a specific embodiment of the invention has been described and shown, variations within the scope of the claims are possible and are contemplated. There is no intention, therefore, oflimitation to the exact disclosure herein made.

'Whatis claimed is: I s g a -ll'In' combination with a high temperature oven having a doorway, substantially H-sectioned guides positight seal between the door and doorway, said sealing means being positioned between the inner face of the door and said innerflanges of the H-sectioned guides, and spring biased compression roller means positioned between the outer face of the door and the said parallel flanges of the L-sectioned flanged columns for biasing the door and said sealing means against said inner flanges of said H-sectioned guides to provide a seal therebetWeen and for maintaining such seal in all sliding positions of Y 4 a 1 the door While permitting ready sliding movement of the door at all times irrespective of oven temperature, said spring biased rollers being protected from the oven temperatures by the refractory material of the door.

2. In combination with a high temperature oven having a doorway, substantially H-sectioned guides positioned along sides of the doorway and each having flanges joined by a cross bar, substantially L-sectioned flanged columns one secured by one of its flanges to a flange of each H-sectioned guide, a slidable refractory door movable guidedly between inner flanges of the- H-sectioned guides and flanges of the L-shaped columns which are parallel with said inner flanges, sealing means unaffected by the heat of the oven for maintaining a gas tight seal between the door and doorway, said sealing means being positioned between the inner face of the door and said inner flanges of the H-sectioned guides,

door while permitting-ready sliding movement of the door flanges of the L-sectioned' flanged columns for biasing the l door and sealing means against said inner flanges of said H-sectioned' guides to provide a seal therebetween and for maintaining suchseal in all sliding positions of the at all times irrespective of oven temperature, said spring biased rollers being protected from the oven temperatures by the refractory material of the door, and guide roller means also supported on-the outer facerof the door and j operable against the cross bars of-the H-sectioned guides to prevent scraping of the side edges of the door against, any portions of the said guides during sliding motion of the door.

References Cited in the flle of this patent UNITED STATES PATENTS Netherlands Aug. 15, 1932 4 

